<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .box{
            width:100px;
            height:100px;
            background-color: #ff6700;

            /*盒子阴影*/
            /*横行偏移10px 纵向偏移10px  阴影颜色 */
          /*  box-shadow:3px 3px rgba(0,0,0,0.3);*/

            /*横行偏移10px 纵向偏移10px 模糊程度 阴影颜色 */
            box-shadow:3px 3px 3px rgba(0,0,0,0.3);

            /*横行偏移10px 纵向偏移10px 模糊程度 阴影扩散范围 阴影颜色 */
            box-shadow:-3px -3px 3px 0px rgba(0,0,0,0.3);
        }
    </style>
</head>
<body>
<div class="box"></div>
</body>
</html>